African tropical wave 99L has potential to develop

By: Dr. Jeff Masters , 3:10 PM GMT on July 30, 2012

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The first African tropical wave of 2012 with a potential to develop is Invest 99L, located in the Eastern Atlantic near 9°N 36°W, midway between the Lesser Antilles Islands and the coast of Africa. Visible satellite loops show a large area of the surrounding atmosphere has a pronounced counter-clockwise spin, though there is no surface circulation. The disturbance's heavy thunderstorm activity is pretty sparse, but appears to be slowly increasing. Water vapor satellite loops show that 99L has a reasonably moist environment, and the latest Saharan air layer analysis shows that the dry air from the Sahara lies well to the north of 99L. WInd shear over the disturbance is a light 5 - 10 knots, and ocean temperatures are 28°C, (82°F) which is well above the 26.5°C (80°F) threshold typically needed to allow formation of a tropical depression.


Figure 1. Morning satellite image of Invest 99L.

Forecast for 99L
Wind shear is expected to remain light for the next five days, and ocean temperatures will remain near 28°C, according to the 8 am EDT run of the SHIPS model. The disturbance is at 9°N, which is close enough to the Equator that the storm will have some difficultly getting spinning. Most of the models are showing some slow development of 99L, with the storm reaching the Lesser Antilles Islands on Saturday, August 3. NHC gave 99L a 20% chance of developing into a tropical depression by Wednesday morning. I expect the storm will have trouble with dry air at times this week as it crosses the Atlantic, but I give 99L a 50% chance of eventually developing into Tropical Storm Ernesto sometime in the next ten days. Residents and visitors to the Lesser Antilles Islands should anticipate heavy rains and strong winds from 99L beginning to affect the islands as early as Friday night. The long-range fate of 99L is uncertain, but a trough of low pressure is expected to be present over the Eastern U.S. early next week, which would be capable of turning 99L more to the northwest.

Hot in the Central U.S.
The heat in America's heartland continued on Sunday, with Wichita, KS hitting 111°F, just 3° short of their all-time hottest temperature of 114° set on 8/12/1936. Other notable highs on Sunday:

111° Coffeyville, KS
111° Winfield, KS
110° Chanute, KS
110° Parsons, KS
109° Joplin, MO (all-time record is 115° on July 14, 1954)

The low temperature in Tulsa, Oklahoma this Monday morning dropped to only 88°F. This is the all-time warmest low temperature in the city since record keeping began in 1905. The previous record warmest minimum temperature was 87°F set on August 2, 2011 and July 16, 1980. The high in Tulsa Monday - Wednesday is expected to reach 110° - 111°, close to the city's all-time hottest temperature of 115° set on August 10, 1936.

Jeff Masters

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One more, this member is thinking NE Florida:

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BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHARLESTON SC
357 PM EDT MON JUL 30 2012

THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHWESTERN EFFINGHAM COUNTY IN SOUTHEAST GEORGIA...
SOUTHERN SCREVEN COUNTY IN SOUTHEAST GEORGIA...
CENTRAL COLLETON COUNTY IN SOUTHEAST SOUTH CAROLINA...
HAMPTON COUNTY IN SOUTHEAST SOUTH CAROLINA...
NORTHERN JASPER COUNTY IN SOUTHEAST SOUTH CAROLINA...

* UNTIL 500 PM EDT

* AT 357 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
SEVERE THUNDERSTORMS...ALONG A LINE EXTENDING FROM CUMMINGS TO
CAPTOLO...MOVING SOUTHEAST AT 10 MPH.

PREPARE NOW FOR THE FOLLOWING HAZARDS...
DAMAGING WINDS IN EXCESS OF 60 MPH...
HAIL UP TO QUARTER SIZE...

* SOME LOCATIONS IN THE WARNING INCLUDE...
CAPTOLO...CUMMINGS...SHIRLEY...SCOTIA...FURMAN...E ARLY BRANCH...
NEWINGTON...WALTERBORO...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE SHELTER AS THUNDERSTORMS APPROACH.

REPORT HAIL...DOWNED TREES...LIMBS...AND POWER LINES DIRECTLY TO THE
CHARLESTON NATIONAL WEATHER SERVICE AT 1-888-383-2024...WHEN IT IS
SAFE TO DO SO.
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Quoting wxchaser97:
This wouldn't be good.


We shouldn't worry about landfall locations until 99L actually develops. Good afternoon everyone!
Member Since: June 18, 2010 Posts: 0 Comments: 507
...................might be some damage and flooding out of these waves that keep coming in off the gulf,stay safe up there folks
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Quoting mrsalagranny:
Be careful hun.Looks like the tropics are coming alive.


Looks like it, but I'm only here until this weekend, visiting my son, then I head back home to Louisiana, Rita/Ike/Gustav country. But I'm on a ten year hiatus from hurricanes and have a few years left on that. *S*
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This wouldn't be good.
Member Since: March 16, 2012 Posts: 123 Comments: 7887
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Quoting aislinnpaps:


Navarre, Florida has been getting hit. Winds been hard enough to blow the rain under the patio roof so I'm forced inside. I'm hoping the next band is the last so I can head out to Destin.
Be careful hun.Looks like the tropics are coming alive.
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Quoting washingtonian115:
Charleston S.C it is then.J/K J/K.I know after Hugo those people don't wanna see another storm come their way.
Lord I hope not. My hometown is still showing scars from Hugo in numerous of places.
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Quoting mrsalagranny:
Looks like I am fixing to get some bad weather here in Loxley Ala.


Navarre, Florida has been getting hit. Winds been hard enough to blow the rain under the patio roof so I'm forced inside. I'm hoping the next band is the last so I can head out to Destin.
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Quoting trHUrrIXC5MMX:
ANOTHER HURRICANE IRENE?
Not as strong as Irene or Earl IMO. Maybe Category 1 or 2. It's just few runs from GPS members, but first 99L have to develops.
Member Since: August 1, 2011 Posts: 23 Comments: 7471
BLAME HUMANS FOR ARCTIC SEA ICE LOSS

Analysis by Kieran Mulvaney%uFFFD
Mon Jul 30, 2012 10:00 AM ET%uFFFD

At least 70 percent, and as much as 95 percent, of sea ice loss in the Arctic is the result of human activities such as the burning of greenhouse gases, according to a new study.

According to the National Snow and Ice Data Center (NSIDC), summer sea ice extent in the Arctic is declining by approximately 12 percent per decade; 2007 and 2011 experienced the lowest summer sea ice levels on record, and NSIDC director Mark Serreze has said that this year's ice is in a "sorry state", at the extreme low end of the satellite record for this time of year and on track to be similar to 2007.

But how much of that change is the result of global warming, and how much can be attributed to natural cycles? The new study, published in the journal Environmental Research Letters, set out to answer that very question.

<>a href=" BLAME HUMANS FOR ARCTIC SEA ICE LOSS Analysis by Kieran Mulvaney Mon Jul 30, 2012 10:00 AM ET At least 70 percent, and as much as 95 percent, of sea ice loss in the Arctic is the result of human activities such as the burning of greenhouse gases, according to a new study. According to the National Snow and Ice Data Center (NSIDC), summer sea ice extent in the Arctic is declining by approximately 12 percent per decade; 2007 and 2011 experienced the lowest summer sea ice levels on record, and NSIDC director Mark Serreze has said that this year's ice is in a "sorry state", at the extreme low end of the satellite record for this time of year and on track to be similar to 2007. But how much of that change is the result of global warming, and how much can be attributed to natural cycles? The new study, published in the journal Environmental Research Letters, set out to answer that very question.

http://news.discovery.com/earth/arctic-sea-ice-lo ss-at-least-70-human-caused-120730.html
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All of them are from 12Z today






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Quoting SouthTampa:
Open image in a new tab/window. It is as big as your browser window.
Thanks for the tip :)
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Quoting Bluestorm5:
974 mb? It's hard to read the numbers.
Yes it is 974mb
Members that have landfalling storms
Member Since: March 16, 2012 Posts: 123 Comments: 7887
ANOTHER HURRICANE IRENE?
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Blog update:

Tropical wave 99L has a chance to develop in the Atlantic

Please check it out.
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18Z GFS...only one run though but hmmm
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I'm surprise that nobody is talking about the tropical wave East of Puerto Rico,is has been growing in size since yesterday,if it goes North of the island we might see some type of development (IMO).
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Quoting Bluestorm5:
974 mb? It's hard to read the numbers.
Open image in a new tab/window. It is as big as your browser window.
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Quoting Bluestorm5:
974 mb? It's hard to read the numbers.

Yep.

Here's another one, just grazes the East Coast:



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Quoting MAweatherboy1:
Another new ensemble member from the 12z GFS... It's thinking SE:

Charleston S.C it is then.J/K J/K.I know after Hugo those people don't wanna see another storm come their way.
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Quoting TropicalAnalystwx13:

Northeast quadrant FTW.
LOL guess we'll be both in the worst side of the hurricane if that was to occurs.
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Quoting MAweatherboy1:
Another new ensemble member from the 12z GFS... It's thinking SE:

974 mb? It's hard to read the numbers.
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Quoting LargoFl:
.............................lets see what the 5pm says

Broad circulation if any.
Its frontal
Mostly over land
Id be suprised if 5pm says anything
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Quoting Tazmanian:
YAY USA has 17 we pulled a head in too 1st place
China and USA is tied at 17 now. However, China is leading 9-5 in gold counts.
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CI# /Pressure/ Vmax
3.3 / 986.5mb/ 51.0kt


Final T# Adj T# Raw T#
3.3 3.7 5.5
Member Since: March 16, 2012 Posts: 123 Comments: 7887
Looks like I am fixing to get some bad weather here in Loxley Ala.
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AL992012 - INVEST

Storm Relative 1km Geostationary Visible Imagery



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Quoting MAweatherboy1:
Another new ensemble member from the 12z GFS... It's thinking SE:


Northeast quadrant FTW.
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Another new ensemble member from the 12z GFS... It's thinking SE:

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Quoting stormchaser19:
North every way
If 99L want to be a strong storm, it must miss Hispaniola... and I don't see that happening.
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.............................lets see what the 5pm says
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YAY USA has 17 we pulled a head in too 1st place
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Quoting GeorgiaStormz:


why were the oceans so cold
especially the southern oceans
seems strange considering how warm the land was


During La Nina, the majority of the oceans are colder than normal. Btw, just because the US was so warm doesn't mean the entire global land masses were also as warm.
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482. CJ5
Finally something to watch. If it stay relatively south it should have a decent environment; lower shear, less SAL.
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Quoting BahaHurican:
The only Caribbean hope for a medal in swimming is getting ready to swim now, a young lady from Jamaica, Alia Atkinson.

BTW, the BOSS place to check results on events is the official website...

Edit: and she just came 4th!!!! WOW!!!
Booooooo !!!! You know I love you to death but the Cayman Islands has excellent swimmers competing.
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Saola is becoming a beautiful typhoon. Not 55 knots anymore.

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Quoting washingtonian115:
Interesting that it keeps showing a hurricane..and look at that low in the caribbean...

That's just one ensemble member, not all of them are that strong, though it would make sense for a stronger storm to form if it went north like that, kind of like what the CMC has been saying.
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Quoting MAweatherboy1:

This is looking more and more like an East coast storm.

The 12z GFS ensemble members seem to be taking it north despite the GFS itself taking it south:

Interesting that it keeps showing a hurricane..and look at that low in the caribbean...
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Quoting MAweatherboy1:

This is looking more and more like an East coast storm.

The 12z GFS ensemble members seem to be taking it north despite the GFS itself taking it south:



The GFS pegged debbie
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Quoting wunderkidcayman:


B,C or D but mainly C or D

I agree
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Quoting MAweatherboy1:

This is looking more and more like an East coast storm.

The 12z GFS ensemble members seem to be taking it north despite the GFS itself taking it south:

So the gfs goes south but gfs ensemble goes north. Who will win, I think ensemble.
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Quoting wunderkidcayman:

no tracks into the Caribbean shear will not be any problem for it what so ever when it does
If it does track into the Caribbean shear WILL tear it to pieces which is why I am hoping it does. Shear has only been decreasing for a couple hours at a time but mostly running 30-50 mph.
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Quoting stormchaser19:
North every way

This is looking more and more like an East coast storm.

The 12z GFS ensemble members seem to be taking it north despite the GFS itself taking it south:

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.................wow the storms really cooled off the gulf coast side, dropped the temps down 20 degree's
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Quoting 19N81W:
this system has an awful lot to overcome...let alone get out of the itcz....that being said with the high in place and its already very low lattitude I doubt it making a turn sharp enough to miss the caribbean....it would have to start turning by tonight tomorrow...just dont see it. I think its coming in to the caribbean where it will likely die or just be a rainmaker...didnt the euro put it in the caribbean?


I wouldn't be surprised if it overcomes them, truth be told. We've had countless systems the last few years overcome way worse.
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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.